Microtubules originate asymmetrically at the somatic Golgi and are guided via Kinesin2 to maintain polarity in neurons
Abstract
Neurons contain polarised microtubule arrays essential for neuronal function. How microtubule nucleation and polarity are regulated within neurons remains unclear. We show that γ-tubulin localises asymmetrically to the somatic Golgi within Drosophila neurons. Microtubules originate from the Golgi with an initial growth preference towards the axon. Their growing plus ends also turn towards and into the axon, adding to the plus-end-out microtubule pool. Any plus ends that reach a dendrite, however, do not readily enter, maintaining minus-end-out polarity. Both turning towards the axon and exclusion from dendrites depend on Kinesin-2, a plus-end-associated motor that guides growing plus ends along adjacent microtubules. We propose that Kinesin-2 engages with a polarised microtubule network within the soma to guide growing microtubules towards the axon; while at dendrite entry sites engagement with microtubules of opposite polarity generates a backward stalling force that prevents entry into dendrites and thus maintains minus-end-out polarity within proximal dendrites.
Data availability
All data generated or analysed during this study are included in the manuscript and supporting files. Source data files have been provided for Figure 6 and 7.
Article and author information
Author details
Funding
Wellcome (105653/Z/14/Z)
- Amrita Mukherjee
- Paul S Brooks
- Paul T Conduit
Isaac Newton Trust (18.23(p))
- Amrita Mukherjee
- Paul T Conduit
Association pour la Recherche sur le Cancer (PJA 20181208148)
- Fred Bernard
- Antoine Guichet
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Reviewing Editor
- Yukiko M Yamashita, University of Michigan, United States
Version history
- Received: May 15, 2020
- Accepted: July 12, 2020
- Accepted Manuscript published: July 13, 2020 (version 1)
- Version of Record published: July 31, 2020 (version 2)
- Version of Record updated: August 3, 2020 (version 3)
Copyright
© 2020, Mukherjee et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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